This report provides the number and proportion of "opioid-tolerant-only" episodes of transdermal fentanyl that were prescribed to patients with evidence of prior‐established “opioid tolerance” by dose of transdermal fentanyl. This analysis only assesses the first eligible transdermal fentanyl episode per user, by dose. Data from January 1, 2009 to December 31, 2013 from 15 Data Partners contributing to the Mini-Sentinel Distributed Database (MSDD) were included in this report. The request was distributed to two Data Partners in March 2016 and to the remaining 13 participating Data Partners in April 2016.